For example, a pipe joint unit disclosed in Japanese Examined Patent Application Publication No. 6-31669 (B2) includes a first pipe member having a male joint part, a second pipe member having a female joint part, an engagement member as a pipe joint member for engaging the male joint part and the female joint part, and a semi-cylindrical member used for disengaging the engagement member.
The female joint part has a generally tubular shape and is formed with openings on its circumference. The engagement member includes elastic arm portions, engagement portions at ends of the elastic arm portions to engage with the openings of the female joint part, and tapered pressure-receiving surfaces at opposite ends of the elastic arm portions. The semi-cylindrical member has a tapered pressing surface on an end.
When the male joint part is received in the female joint part, the engagement member is disposed between peripheral walls of the first and second pipe members such that the elastic arm portions extend in an axial direction between the peripheral wall of the first and second pipe members, and the engagement portions are engaged with the openings of the female joint part. Thus, the first and second pipe members are engaged through the engagement member.
For separating the first and second pipe members coupled in the above condition, the semi-cylindrical member, which is loosely mounted on the first pipe member, is slid in the axial direction so that the pressing surface is pressed into contact with the pressure receiving surfaces of the elastic arm portions of the engagement member. As such, the elastic arm portions are elastically deformed in a radial direction, and thus the engagement portions are removed from the openings. Accordingly, the engagement member is disengaged from the female joint part, and thus the first and second pipe members are separated.
In the disclosed pipe joint unit, the engagement member is engaged with the female joint part by inserting the male joint part into the female joint part. Namely, the first pipe member and the second pipe member are coupled with the engagement member by a one-touch operation.
However, because the engagement member is rotatable about the first pipe member, it will be rotated between the male joint part and the female joint part. As a result, one of the first pipe member and the second pipe member will be rotated in association with the rotation of the engagement member. The rotation will cause wear of sealing portions, and leakage of an internal fluid such as a refrigerant due to vibrations.
Further, such a pipe joint unit may be employed to couple rubber hoses. For example, the male joint part and the female joint part may be coupled to ends of the rubber hoses, respectively. In this case, the rotation of the engagement member will result in interference of the rubber hoses with peripheral parts if the rubber hoses are unevenly arranged.